SmallCounter

Define a class SmallCounter that has methods tick, untick, and value. The tick method should increment an internal field by 1; the untick method should decrement it by 1. The internal counter field should start 0. The value method return the current value.

Your SmallCounter should only ever be between 0 and 10. If someone calls untick when the counter is 0, it should stay at 0; if someone calls tick when the counter is 10, it should stay at 10.